11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/kernel/ptrace.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 71da177e4SLinus Torvalds * to continually duplicate across every architecture. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 10c59ede7bSRandy.Dunlap #include <linux/capability.h> 111da177e4SLinus Torvalds #include <linux/module.h> 121da177e4SLinus Torvalds #include <linux/sched.h> 131da177e4SLinus Torvalds #include <linux/errno.h> 141da177e4SLinus Torvalds #include <linux/mm.h> 151da177e4SLinus Torvalds #include <linux/highmem.h> 161da177e4SLinus Torvalds #include <linux/pagemap.h> 171da177e4SLinus Torvalds #include <linux/ptrace.h> 181da177e4SLinus Torvalds #include <linux/security.h> 197ed20e1aSJesper Juhl #include <linux/signal.h> 20a5cb013dSAl Viro #include <linux/audit.h> 21b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 22f17d30a8SAdrian Bunk #include <linux/syscalls.h> 233a709703SRoland McGrath #include <linux/uaccess.h> 242225a122SSuresh Siddha #include <linux/regset.h> 25bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.h> 26f701e5b7SVladimir Zapolskiy #include <linux/cn_proc.h> 271da177e4SLinus Torvalds 28bf53de90SMarkus Metzger 2962c124ffSTejun Heo static int ptrace_trapping_sleep_fn(void *flags) 3062c124ffSTejun Heo { 3162c124ffSTejun Heo schedule(); 3262c124ffSTejun Heo return 0; 3362c124ffSTejun Heo } 3462c124ffSTejun Heo 35bf53de90SMarkus Metzger /* 361da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 371da177e4SLinus Torvalds * move it to the ptrace list. 381da177e4SLinus Torvalds * 391da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 401da177e4SLinus Torvalds */ 4136c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 421da177e4SLinus Torvalds { 43f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 44f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 451da177e4SLinus Torvalds child->parent = new_parent; 461da177e4SLinus Torvalds } 471da177e4SLinus Torvalds 48e3bd058fSTejun Heo /** 49e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 50e3bd058fSTejun Heo * @child: ptracee to be unlinked 511da177e4SLinus Torvalds * 520e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 530e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 540e9f0a4aSTejun Heo * state. 550e9f0a4aSTejun Heo * 560e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 570e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 580e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 590e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 600e9f0a4aSTejun Heo * 610e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 620e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 630e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 640e9f0a4aSTejun Heo * up from TASK_TRACED. 650e9f0a4aSTejun Heo * 660e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 670e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 680e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 690e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 700e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 710e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 72e3bd058fSTejun Heo * 73e3bd058fSTejun Heo * CONTEXT: 74e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 751da177e4SLinus Torvalds */ 7636c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 771da177e4SLinus Torvalds { 785ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 795ecfbae0SOleg Nesterov 801da177e4SLinus Torvalds child->ptrace = 0; 811da177e4SLinus Torvalds child->parent = child->real_parent; 82f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 831da177e4SLinus Torvalds 841da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 850e9f0a4aSTejun Heo 861da177e4SLinus Torvalds /* 8773ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 8873ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 8973ddff2bSTejun Heo */ 9073ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 9173ddff2bSTejun Heo task_clear_jobctl_trapping(child); 9273ddff2bSTejun Heo 9373ddff2bSTejun Heo /* 94a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 950e9f0a4aSTejun Heo * @child isn't dead. 961da177e4SLinus Torvalds */ 970e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 980e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 990e9f0a4aSTejun Heo child->signal->group_stop_count)) 100a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1010e9f0a4aSTejun Heo 1020e9f0a4aSTejun Heo /* 1030e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1040e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1050e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1060e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1070e9f0a4aSTejun Heo */ 108a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 1090e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 1100e9f0a4aSTejun Heo 1111da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 114755e276bSTejun Heo /** 115755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 116755e276bSTejun Heo * @child: ptracee to check for 117755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 118755e276bSTejun Heo * 119755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 120755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 121755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 122755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 123755e276bSTejun Heo * state. 124755e276bSTejun Heo * 125755e276bSTejun Heo * CONTEXT: 126755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 127755e276bSTejun Heo * 128755e276bSTejun Heo * RETURNS: 129755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1301da177e4SLinus Torvalds */ 131755e276bSTejun Heo int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1321da177e4SLinus Torvalds { 1331da177e4SLinus Torvalds int ret = -ESRCH; 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds /* 1361da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1371da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1381da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1391da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1401da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1411da177e4SLinus Torvalds */ 1421da177e4SLinus Torvalds read_lock(&tasklist_lock); 143c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 144c0c0b649SOleg Nesterov /* 145c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 146c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 147c0c0b649SOleg Nesterov */ 1481da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 149321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 150544b2c91STejun Heo if (ignore_state || (task_is_traced(child) && 151544b2c91STejun Heo !(child->jobctl & JOBCTL_LISTENING))) 152321fb561SOleg Nesterov ret = 0; 1531da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1561da177e4SLinus Torvalds 157755e276bSTejun Heo if (!ret && !ignore_state) 15885ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds /* All systems go.. */ 1611da177e4SLinus Torvalds return ret; 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds 16469f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 16569f594a3SEric Paris { 16669f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 16769f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 16869f594a3SEric Paris else 16969f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 17069f594a3SEric Paris } 17169f594a3SEric Paris 172006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 173ab8d11beSMiklos Szeredi { 174c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 175b6dff3ecSDavid Howells 176df26c40eSEric W. Biederman /* May we inspect the given task? 177df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 178df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 179df26c40eSEric W. Biederman * 180df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 181df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 182df26c40eSEric W. Biederman * or halting the specified task is impossible. 183df26c40eSEric W. Biederman */ 184df26c40eSEric W. Biederman int dumpable = 0; 185df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 186df26c40eSEric W. Biederman if (task == current) 187df26c40eSEric W. Biederman return 0; 188c69e8d9cSDavid Howells rcu_read_lock(); 189c69e8d9cSDavid Howells tcred = __task_cred(task); 1908409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 1918409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 1928409cca7SSerge E. Hallyn cred->uid == tcred->suid && 1938409cca7SSerge E. Hallyn cred->uid == tcred->uid && 1948409cca7SSerge E. Hallyn cred->gid == tcred->egid && 1958409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 1968409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 1978409cca7SSerge E. Hallyn goto ok; 19869f594a3SEric Paris if (ptrace_has_cap(tcred->user->user_ns, mode)) 1998409cca7SSerge E. Hallyn goto ok; 200c69e8d9cSDavid Howells rcu_read_unlock(); 201ab8d11beSMiklos Szeredi return -EPERM; 2028409cca7SSerge E. Hallyn ok: 203c69e8d9cSDavid Howells rcu_read_unlock(); 204ab8d11beSMiklos Szeredi smp_rmb(); 205df26c40eSEric W. Biederman if (task->mm) 2066c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 20769f594a3SEric Paris if (!dumpable && !ptrace_has_cap(task_user_ns(task), mode)) 208ab8d11beSMiklos Szeredi return -EPERM; 209ab8d11beSMiklos Szeredi 2109e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 211ab8d11beSMiklos Szeredi } 212ab8d11beSMiklos Szeredi 213006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 214ab8d11beSMiklos Szeredi { 215ab8d11beSMiklos Szeredi int err; 216ab8d11beSMiklos Szeredi task_lock(task); 217006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 218ab8d11beSMiklos Szeredi task_unlock(task); 2193a709703SRoland McGrath return !err; 220ab8d11beSMiklos Szeredi } 221ab8d11beSMiklos Szeredi 2223544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 2233544d72aSTejun Heo unsigned long flags) 2241da177e4SLinus Torvalds { 2253544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2261da177e4SLinus Torvalds int retval; 227f5b40e36SLinus Torvalds 2283544d72aSTejun Heo /* 2293544d72aSTejun Heo * SEIZE will enable new ptrace behaviors which will be implemented 2303544d72aSTejun Heo * gradually. SEIZE_DEVEL is used to prevent applications 2313544d72aSTejun Heo * expecting full SEIZE behaviors trapping on kernel commits which 2323544d72aSTejun Heo * are still in the process of implementing them. 2333544d72aSTejun Heo * 2343544d72aSTejun Heo * Only test programs for new ptrace behaviors being implemented 2353544d72aSTejun Heo * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. 2363544d72aSTejun Heo * 2373544d72aSTejun Heo * Once SEIZE behaviors are completely implemented, this flag and 2383544d72aSTejun Heo * the following test will be removed. 2393544d72aSTejun Heo */ 2403544d72aSTejun Heo retval = -EIO; 2413544d72aSTejun Heo if (seize && !(flags & PTRACE_SEIZE_DEVEL)) 2423544d72aSTejun Heo goto out; 2433544d72aSTejun Heo 244a5cb013dSAl Viro audit_ptrace(task); 245a5cb013dSAl Viro 2461da177e4SLinus Torvalds retval = -EPERM; 247b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 248b79b7ba9SOleg Nesterov goto out; 249bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 250f5b40e36SLinus Torvalds goto out; 251f5b40e36SLinus Torvalds 252f2f0b00aSOleg Nesterov /* 253f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 2545e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2555e751e99SDavid Howells * under ptrace. 256d84f4f99SDavid Howells */ 257793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2589b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 259d84f4f99SDavid Howells goto out; 2604b105cbbSOleg Nesterov 261f5b40e36SLinus Torvalds task_lock(task); 262006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2634b105cbbSOleg Nesterov task_unlock(task); 2641da177e4SLinus Torvalds if (retval) 2654b105cbbSOleg Nesterov goto unlock_creds; 2661da177e4SLinus Torvalds 2674b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 268b79b7ba9SOleg Nesterov retval = -EPERM; 269b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2704b105cbbSOleg Nesterov goto unlock_tasklist; 271f2f0b00aSOleg Nesterov if (task->ptrace) 2724b105cbbSOleg Nesterov goto unlock_tasklist; 273b79b7ba9SOleg Nesterov 274f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2753544d72aSTejun Heo if (seize) 2763544d72aSTejun Heo task->ptrace |= PT_SEIZED; 277f1c84daeSEric Paris if (ns_capable(task_user_ns(task), CAP_SYS_PTRACE)) 2781da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds __ptrace_link(task, current); 2813544d72aSTejun Heo 2823544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2833544d72aSTejun Heo if (!seize) 28433e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 285b79b7ba9SOleg Nesterov 286d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 287d79fdd6dSTejun Heo 288d79fdd6dSTejun Heo /* 28973ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 290d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 291d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 292d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 293d79fdd6dSTejun Heo * for the transition to complete before returning from this 294d79fdd6dSTejun Heo * function. 295d79fdd6dSTejun Heo * 296d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 297d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 298d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 299d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 300d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 301d79fdd6dSTejun Heo * 302d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 303d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 304d79fdd6dSTejun Heo */ 3057dd3db54STejun Heo if (task_is_stopped(task) && 30673ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 307d79fdd6dSTejun Heo signal_wake_up(task, 1); 308d79fdd6dSTejun Heo 309d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 310d79fdd6dSTejun Heo 311b79b7ba9SOleg Nesterov retval = 0; 3124b105cbbSOleg Nesterov unlock_tasklist: 3134b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3144b105cbbSOleg Nesterov unlock_creds: 3159b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 316f5b40e36SLinus Torvalds out: 317f701e5b7SVladimir Zapolskiy if (!retval) { 31862c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 31962c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 320f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 321f701e5b7SVladimir Zapolskiy } 322f701e5b7SVladimir Zapolskiy 3231da177e4SLinus Torvalds return retval; 3241da177e4SLinus Torvalds } 3251da177e4SLinus Torvalds 326f2f0b00aSOleg Nesterov /** 327f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 328f2f0b00aSOleg Nesterov * 329f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 330f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 331f2f0b00aSOleg Nesterov */ 332e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 333f2f0b00aSOleg Nesterov { 334f2f0b00aSOleg Nesterov int ret = -EPERM; 335f2f0b00aSOleg Nesterov 3364b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3374b105cbbSOleg Nesterov /* Are we already being traced? */ 338f2f0b00aSOleg Nesterov if (!current->ptrace) { 339f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 340f2f0b00aSOleg Nesterov /* 341f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 342f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 343f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 344f2f0b00aSOleg Nesterov */ 345f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 346f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 347f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 348f2f0b00aSOleg Nesterov } 349f2f0b00aSOleg Nesterov } 3504b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3514b105cbbSOleg Nesterov 352f2f0b00aSOleg Nesterov return ret; 353f2f0b00aSOleg Nesterov } 354f2f0b00aSOleg Nesterov 35539c626aeSOleg Nesterov /* 35639c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 35739c626aeSOleg Nesterov */ 35839c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 35939c626aeSOleg Nesterov { 36039c626aeSOleg Nesterov int ret; 36139c626aeSOleg Nesterov spin_lock(&sigh->siglock); 36239c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 36339c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 36439c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 36539c626aeSOleg Nesterov return ret; 36639c626aeSOleg Nesterov } 36739c626aeSOleg Nesterov 36839c626aeSOleg Nesterov /* 36939c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 37039c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 37139c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 37239c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 37339c626aeSOleg Nesterov * 37439c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 37539c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 37639c626aeSOleg Nesterov * If it should reap itself, return true. 37739c626aeSOleg Nesterov * 378a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 379a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 380a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 381a7f0765eSOleg Nesterov * do_wait(). 38239c626aeSOleg Nesterov */ 38339c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 38439c626aeSOleg Nesterov { 3859843a1e9SOleg Nesterov bool dead; 3869843a1e9SOleg Nesterov 38739c626aeSOleg Nesterov __ptrace_unlink(p); 38839c626aeSOleg Nesterov 3899843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 3909843a1e9SOleg Nesterov return false; 3919843a1e9SOleg Nesterov 3929843a1e9SOleg Nesterov dead = !thread_group_leader(p); 3939843a1e9SOleg Nesterov 3949843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 39539c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 3969843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 397a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 398a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 3999843a1e9SOleg Nesterov dead = true; 40039c626aeSOleg Nesterov } 401a7f0765eSOleg Nesterov } 40239c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 4039843a1e9SOleg Nesterov if (dead) 40439c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 4059843a1e9SOleg Nesterov return dead; 40639c626aeSOleg Nesterov } 40739c626aeSOleg Nesterov 408e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4091da177e4SLinus Torvalds { 41039c626aeSOleg Nesterov bool dead = false; 4114576145cSOleg Nesterov 4127ed20e1aSJesper Juhl if (!valid_signal(data)) 4131da177e4SLinus Torvalds return -EIO; 4141da177e4SLinus Torvalds 4151da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4161da177e4SLinus Torvalds ptrace_disable(child); 4177d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4181da177e4SLinus Torvalds 41995c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 42039c626aeSOleg Nesterov /* 42139c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 42239c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 42339c626aeSOleg Nesterov */ 42495c3eb76SOleg Nesterov if (child->ptrace) { 42595c3eb76SOleg Nesterov child->exit_code = data; 4264576145cSOleg Nesterov dead = __ptrace_detach(current, child); 42795c3eb76SOleg Nesterov } 4281da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4291da177e4SLinus Torvalds 430f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4314576145cSOleg Nesterov if (unlikely(dead)) 4324576145cSOleg Nesterov release_task(child); 4334576145cSOleg Nesterov 4341da177e4SLinus Torvalds return 0; 4351da177e4SLinus Torvalds } 4361da177e4SLinus Torvalds 43739c626aeSOleg Nesterov /* 438c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 439c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 440c7e49c14SOleg Nesterov * and reacquire the lock. 44139c626aeSOleg Nesterov */ 44239c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 443c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 444c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 44539c626aeSOleg Nesterov { 44639c626aeSOleg Nesterov struct task_struct *p, *n; 44739c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 44839c626aeSOleg Nesterov 449c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 450c7e49c14SOleg Nesterov return; 451c7e49c14SOleg Nesterov 45239c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 45339c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 45439c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 45539c626aeSOleg Nesterov } 45639c626aeSOleg Nesterov 457c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 45839c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 45939c626aeSOleg Nesterov 46039c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 46139c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 46239c626aeSOleg Nesterov release_task(p); 46339c626aeSOleg Nesterov } 464c7e49c14SOleg Nesterov 465c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 46639c626aeSOleg Nesterov } 46739c626aeSOleg Nesterov 4681da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4691da177e4SLinus Torvalds { 4701da177e4SLinus Torvalds int copied = 0; 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvalds while (len > 0) { 4731da177e4SLinus Torvalds char buf[128]; 4741da177e4SLinus Torvalds int this_len, retval; 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4771da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4781da177e4SLinus Torvalds if (!retval) { 4791da177e4SLinus Torvalds if (copied) 4801da177e4SLinus Torvalds break; 4811da177e4SLinus Torvalds return -EIO; 4821da177e4SLinus Torvalds } 4831da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4841da177e4SLinus Torvalds return -EFAULT; 4851da177e4SLinus Torvalds copied += retval; 4861da177e4SLinus Torvalds src += retval; 4871da177e4SLinus Torvalds dst += retval; 4881da177e4SLinus Torvalds len -= retval; 4891da177e4SLinus Torvalds } 4901da177e4SLinus Torvalds return copied; 4911da177e4SLinus Torvalds } 4921da177e4SLinus Torvalds 4931da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4941da177e4SLinus Torvalds { 4951da177e4SLinus Torvalds int copied = 0; 4961da177e4SLinus Torvalds 4971da177e4SLinus Torvalds while (len > 0) { 4981da177e4SLinus Torvalds char buf[128]; 4991da177e4SLinus Torvalds int this_len, retval; 5001da177e4SLinus Torvalds 5011da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5021da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5031da177e4SLinus Torvalds return -EFAULT; 5041da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 5051da177e4SLinus Torvalds if (!retval) { 5061da177e4SLinus Torvalds if (copied) 5071da177e4SLinus Torvalds break; 5081da177e4SLinus Torvalds return -EIO; 5091da177e4SLinus Torvalds } 5101da177e4SLinus Torvalds copied += retval; 5111da177e4SLinus Torvalds src += retval; 5121da177e4SLinus Torvalds dst += retval; 5131da177e4SLinus Torvalds len -= retval; 5141da177e4SLinus Torvalds } 5151da177e4SLinus Torvalds return copied; 5161da177e4SLinus Torvalds } 5171da177e4SLinus Torvalds 5184abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5191da177e4SLinus Torvalds { 5201da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 5211da177e4SLinus Torvalds 5221da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 5231da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 5241da177e4SLinus Torvalds 5251da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 5261da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 5291da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 5301da177e4SLinus Torvalds 5311da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 5321da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 5351da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 5361da177e4SLinus Torvalds 5371da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 5381da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 5391da177e4SLinus Torvalds 5401da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 5411da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 5421da177e4SLinus Torvalds 5431da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 5441da177e4SLinus Torvalds } 5451da177e4SLinus Torvalds 546e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5471da177e4SLinus Torvalds { 548e4961254SOleg Nesterov unsigned long flags; 5491da177e4SLinus Torvalds int error = -ESRCH; 5501da177e4SLinus Torvalds 551e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5521da177e4SLinus Torvalds error = -EINVAL; 5531da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 554e16b2781SRoland McGrath *info = *child->last_siginfo; 5551da177e4SLinus Torvalds error = 0; 5561da177e4SLinus Torvalds } 557e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5581da177e4SLinus Torvalds } 5591da177e4SLinus Torvalds return error; 5601da177e4SLinus Torvalds } 5611da177e4SLinus Torvalds 562e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5631da177e4SLinus Torvalds { 564e4961254SOleg Nesterov unsigned long flags; 5651da177e4SLinus Torvalds int error = -ESRCH; 5661da177e4SLinus Torvalds 567e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5681da177e4SLinus Torvalds error = -EINVAL; 5691da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 570e16b2781SRoland McGrath *child->last_siginfo = *info; 5711da177e4SLinus Torvalds error = 0; 5721da177e4SLinus Torvalds } 573e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5741da177e4SLinus Torvalds } 5751da177e4SLinus Torvalds return error; 5761da177e4SLinus Torvalds } 5771da177e4SLinus Torvalds 57836df29d7SRoland McGrath 57936df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 58036df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 58136df29d7SRoland McGrath #else 58236df29d7SRoland McGrath #define is_singlestep(request) 0 58336df29d7SRoland McGrath #endif 58436df29d7SRoland McGrath 5855b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5865b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5875b88abbfSRoland McGrath #else 5885b88abbfSRoland McGrath #define is_singleblock(request) 0 5895b88abbfSRoland McGrath #endif 5905b88abbfSRoland McGrath 59136df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 59236df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 59336df29d7SRoland McGrath #else 59436df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 59536df29d7SRoland McGrath #endif 59636df29d7SRoland McGrath 5974abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5984abf9869SNamhyung Kim unsigned long data) 59936df29d7SRoland McGrath { 60036df29d7SRoland McGrath if (!valid_signal(data)) 60136df29d7SRoland McGrath return -EIO; 60236df29d7SRoland McGrath 60336df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 60436df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 60536df29d7SRoland McGrath else 60636df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 60736df29d7SRoland McGrath 60836df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 60936df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 61036df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 61136df29d7SRoland McGrath else 61236df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 61336df29d7SRoland McGrath #endif 61436df29d7SRoland McGrath 6155b88abbfSRoland McGrath if (is_singleblock(request)) { 6165b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6175b88abbfSRoland McGrath return -EIO; 6185b88abbfSRoland McGrath user_enable_block_step(child); 6195b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 62036df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 62136df29d7SRoland McGrath return -EIO; 62236df29d7SRoland McGrath user_enable_single_step(child); 6233a709703SRoland McGrath } else { 62436df29d7SRoland McGrath user_disable_single_step(child); 6253a709703SRoland McGrath } 62636df29d7SRoland McGrath 62736df29d7SRoland McGrath child->exit_code = data; 6280666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 62936df29d7SRoland McGrath 63036df29d7SRoland McGrath return 0; 63136df29d7SRoland McGrath } 63236df29d7SRoland McGrath 6332225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6342225a122SSuresh Siddha 6352225a122SSuresh Siddha static const struct user_regset * 6362225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6372225a122SSuresh Siddha { 6382225a122SSuresh Siddha const struct user_regset *regset; 6392225a122SSuresh Siddha int n; 6402225a122SSuresh Siddha 6412225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6422225a122SSuresh Siddha regset = view->regsets + n; 6432225a122SSuresh Siddha if (regset->core_note_type == type) 6442225a122SSuresh Siddha return regset; 6452225a122SSuresh Siddha } 6462225a122SSuresh Siddha 6472225a122SSuresh Siddha return NULL; 6482225a122SSuresh Siddha } 6492225a122SSuresh Siddha 6502225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6512225a122SSuresh Siddha struct iovec *kiov) 6522225a122SSuresh Siddha { 6532225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6542225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6552225a122SSuresh Siddha int regset_no; 6562225a122SSuresh Siddha 6572225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 658c6a0dd7eSSuresh Siddha return -EINVAL; 6592225a122SSuresh Siddha 6602225a122SSuresh Siddha regset_no = regset - view->regsets; 6612225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6622225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6632225a122SSuresh Siddha 6642225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6652225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6662225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6672225a122SSuresh Siddha else 6682225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6692225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6702225a122SSuresh Siddha } 6712225a122SSuresh Siddha 6722225a122SSuresh Siddha #endif 6732225a122SSuresh Siddha 6741da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6754abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6761da177e4SLinus Torvalds { 677fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6781da177e4SLinus Torvalds int ret = -EIO; 679544b2c91STejun Heo siginfo_t siginfo, *si; 6809fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6819fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 682fca26f26STejun Heo unsigned long flags; 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds switch (request) { 68516c3e389SRoland McGrath case PTRACE_PEEKTEXT: 68616c3e389SRoland McGrath case PTRACE_PEEKDATA: 68716c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 68816c3e389SRoland McGrath case PTRACE_POKETEXT: 68916c3e389SRoland McGrath case PTRACE_POKEDATA: 69016c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 69116c3e389SRoland McGrath 6921da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6931da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6941da177e4SLinus Torvalds #endif 6951da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6961da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6971da177e4SLinus Torvalds break; 6981da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6999fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 7001da177e4SLinus Torvalds break; 701e16b2781SRoland McGrath 7021da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 703e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 704e16b2781SRoland McGrath if (!ret) 7059fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 7061da177e4SLinus Torvalds break; 707e16b2781SRoland McGrath 7081da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7099fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 710e16b2781SRoland McGrath ret = -EFAULT; 711e16b2781SRoland McGrath else 712e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7131da177e4SLinus Torvalds break; 714e16b2781SRoland McGrath 715fca26f26STejun Heo case PTRACE_INTERRUPT: 716fca26f26STejun Heo /* 717fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 718fca26f26STejun Heo * control. At least one trap is guaranteed to happen 719fca26f26STejun Heo * after this request. If @child is already trapped, the 720fca26f26STejun Heo * current trap is not disturbed and another trap will 721fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 722fca26f26STejun Heo * 723fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 724fca26f26STejun Heo * the pending condition is cleared regardless. 725fca26f26STejun Heo */ 726fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 727fca26f26STejun Heo break; 728fca26f26STejun Heo 729544b2c91STejun Heo /* 730544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 731544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 732544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 733544b2c91STejun Heo * tracee into STOP. 734544b2c91STejun Heo */ 735fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 736544b2c91STejun Heo signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 737544b2c91STejun Heo 738544b2c91STejun Heo unlock_task_sighand(child, &flags); 739544b2c91STejun Heo ret = 0; 740544b2c91STejun Heo break; 741544b2c91STejun Heo 742544b2c91STejun Heo case PTRACE_LISTEN: 743544b2c91STejun Heo /* 744544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 745544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 746544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 747544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 748544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 749544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 750544b2c91STejun Heo */ 751544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 752544b2c91STejun Heo break; 753544b2c91STejun Heo 754544b2c91STejun Heo si = child->last_siginfo; 755f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 756544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 757544b2c91STejun Heo /* 758f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 759f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 760544b2c91STejun Heo */ 761544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 762544b2c91STejun Heo signal_wake_up(child, true); 763fca26f26STejun Heo ret = 0; 764f9d81f61SOleg Nesterov } 765f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 766fca26f26STejun Heo break; 767fca26f26STejun Heo 7681bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7691bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7701bcf5482SAlexey Dobriyan break; 77136df29d7SRoland McGrath 7729c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7739c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 774e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7759c1a1259SMike Frysinger unsigned long tmp = 0; 7769c1a1259SMike Frysinger 777e0129ef9SOleg Nesterov ret = -ESRCH; 778e0129ef9SOleg Nesterov if (!mm) 779e0129ef9SOleg Nesterov break; 780e0129ef9SOleg Nesterov 7819c1a1259SMike Frysinger switch (addr) { 7829c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 783e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7849c1a1259SMike Frysinger break; 7859c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 786e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 7879c1a1259SMike Frysinger break; 7889c1a1259SMike Frysinger default: 7899c1a1259SMike Frysinger break; 7909c1a1259SMike Frysinger } 791e0129ef9SOleg Nesterov mmput(mm); 7929c1a1259SMike Frysinger 7939fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7949c1a1259SMike Frysinger break; 7959c1a1259SMike Frysinger } 7969c1a1259SMike Frysinger #endif 7979c1a1259SMike Frysinger 79836df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 79936df29d7SRoland McGrath case PTRACE_SINGLESTEP: 80036df29d7SRoland McGrath #endif 8015b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8025b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 8035b88abbfSRoland McGrath #endif 80436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 80536df29d7SRoland McGrath case PTRACE_SYSEMU: 80636df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 80736df29d7SRoland McGrath #endif 80836df29d7SRoland McGrath case PTRACE_SYSCALL: 80936df29d7SRoland McGrath case PTRACE_CONT: 81036df29d7SRoland McGrath return ptrace_resume(child, request, data); 81136df29d7SRoland McGrath 81236df29d7SRoland McGrath case PTRACE_KILL: 81336df29d7SRoland McGrath if (child->exit_state) /* already dead */ 81436df29d7SRoland McGrath return 0; 81536df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 81636df29d7SRoland McGrath 8172225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8182225a122SSuresh Siddha case PTRACE_GETREGSET: 8192225a122SSuresh Siddha case PTRACE_SETREGSET: 8202225a122SSuresh Siddha { 8212225a122SSuresh Siddha struct iovec kiov; 8229fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8232225a122SSuresh Siddha 8242225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8252225a122SSuresh Siddha return -EFAULT; 8262225a122SSuresh Siddha 8272225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8282225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8292225a122SSuresh Siddha return -EFAULT; 8302225a122SSuresh Siddha 8312225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8322225a122SSuresh Siddha if (!ret) 8332225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8342225a122SSuresh Siddha break; 8352225a122SSuresh Siddha } 8362225a122SSuresh Siddha #endif 8371da177e4SLinus Torvalds default: 8381da177e4SLinus Torvalds break; 8391da177e4SLinus Torvalds } 8401da177e4SLinus Torvalds 8411da177e4SLinus Torvalds return ret; 8421da177e4SLinus Torvalds } 843481bed45SChristoph Hellwig 8448053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8456b9c7ed8SChristoph Hellwig { 8466b9c7ed8SChristoph Hellwig struct task_struct *child; 8476b9c7ed8SChristoph Hellwig 8488053bdd5SOleg Nesterov rcu_read_lock(); 849228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 850481bed45SChristoph Hellwig if (child) 851481bed45SChristoph Hellwig get_task_struct(child); 8528053bdd5SOleg Nesterov rcu_read_unlock(); 853f400e198SSukadev Bhattiprolu 854481bed45SChristoph Hellwig if (!child) 8556b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8566b9c7ed8SChristoph Hellwig return child; 857481bed45SChristoph Hellwig } 858481bed45SChristoph Hellwig 8590ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8600ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8610ac15559SChristoph Hellwig #endif 8620ac15559SChristoph Hellwig 8634abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8644abf9869SNamhyung Kim unsigned long, data) 865481bed45SChristoph Hellwig { 866481bed45SChristoph Hellwig struct task_struct *child; 867481bed45SChristoph Hellwig long ret; 868481bed45SChristoph Hellwig 8696b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8706b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8716ea6dd93SHaavard Skinnemoen if (!ret) 8726ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 873481bed45SChristoph Hellwig goto out; 8746b9c7ed8SChristoph Hellwig } 8756b9c7ed8SChristoph Hellwig 8766b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8776b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8786b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8796b9c7ed8SChristoph Hellwig goto out; 8806b9c7ed8SChristoph Hellwig } 881481bed45SChristoph Hellwig 8823544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 8833544d72aSTejun Heo ret = ptrace_attach(child, request, data); 8840ac15559SChristoph Hellwig /* 8850ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 8860ac15559SChristoph Hellwig * a ptrace attach. 8870ac15559SChristoph Hellwig */ 8880ac15559SChristoph Hellwig if (!ret) 8890ac15559SChristoph Hellwig arch_ptrace_attach(child); 890005f18dfSChristoph Hellwig goto out_put_task_struct; 891481bed45SChristoph Hellwig } 892481bed45SChristoph Hellwig 893fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 894fca26f26STejun Heo request == PTRACE_INTERRUPT); 895481bed45SChristoph Hellwig if (ret < 0) 896481bed45SChristoph Hellwig goto out_put_task_struct; 897481bed45SChristoph Hellwig 898481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 899481bed45SChristoph Hellwig 900481bed45SChristoph Hellwig out_put_task_struct: 901481bed45SChristoph Hellwig put_task_struct(child); 902481bed45SChristoph Hellwig out: 903481bed45SChristoph Hellwig return ret; 904481bed45SChristoph Hellwig } 90576647323SAlexey Dobriyan 9064abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9074abf9869SNamhyung Kim unsigned long data) 90876647323SAlexey Dobriyan { 90976647323SAlexey Dobriyan unsigned long tmp; 91076647323SAlexey Dobriyan int copied; 91176647323SAlexey Dobriyan 91276647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 91376647323SAlexey Dobriyan if (copied != sizeof(tmp)) 91476647323SAlexey Dobriyan return -EIO; 91576647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 91676647323SAlexey Dobriyan } 917f284ce72SAlexey Dobriyan 9184abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9194abf9869SNamhyung Kim unsigned long data) 920f284ce72SAlexey Dobriyan { 921f284ce72SAlexey Dobriyan int copied; 922f284ce72SAlexey Dobriyan 923f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 924f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 925f284ce72SAlexey Dobriyan } 926032d82d9SRoland McGrath 92796b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 928032d82d9SRoland McGrath #include <linux/compat.h> 929032d82d9SRoland McGrath 930032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 931032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 932032d82d9SRoland McGrath { 933032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 934032d82d9SRoland McGrath compat_ulong_t word; 935e16b2781SRoland McGrath siginfo_t siginfo; 936032d82d9SRoland McGrath int ret; 937032d82d9SRoland McGrath 938032d82d9SRoland McGrath switch (request) { 939032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 940032d82d9SRoland McGrath case PTRACE_PEEKDATA: 941032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 942032d82d9SRoland McGrath if (ret != sizeof(word)) 943032d82d9SRoland McGrath ret = -EIO; 944032d82d9SRoland McGrath else 945032d82d9SRoland McGrath ret = put_user(word, datap); 946032d82d9SRoland McGrath break; 947032d82d9SRoland McGrath 948032d82d9SRoland McGrath case PTRACE_POKETEXT: 949032d82d9SRoland McGrath case PTRACE_POKEDATA: 950032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 951032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 952032d82d9SRoland McGrath break; 953032d82d9SRoland McGrath 954032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 955032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 956032d82d9SRoland McGrath break; 957032d82d9SRoland McGrath 958e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 959e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 960e16b2781SRoland McGrath if (!ret) 961e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 962e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 963e16b2781SRoland McGrath &siginfo); 964e16b2781SRoland McGrath break; 965e16b2781SRoland McGrath 966e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 967e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 968e16b2781SRoland McGrath if (copy_siginfo_from_user32( 969e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 970e16b2781SRoland McGrath ret = -EFAULT; 971e16b2781SRoland McGrath else 972e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 973e16b2781SRoland McGrath break; 9742225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9752225a122SSuresh Siddha case PTRACE_GETREGSET: 9762225a122SSuresh Siddha case PTRACE_SETREGSET: 9772225a122SSuresh Siddha { 9782225a122SSuresh Siddha struct iovec kiov; 9792225a122SSuresh Siddha struct compat_iovec __user *uiov = 9802225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9812225a122SSuresh Siddha compat_uptr_t ptr; 9822225a122SSuresh Siddha compat_size_t len; 9832225a122SSuresh Siddha 9842225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9852225a122SSuresh Siddha return -EFAULT; 9862225a122SSuresh Siddha 9872225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 9882225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 9892225a122SSuresh Siddha return -EFAULT; 9902225a122SSuresh Siddha 9912225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 9922225a122SSuresh Siddha kiov.iov_len = len; 9932225a122SSuresh Siddha 9942225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9952225a122SSuresh Siddha if (!ret) 9962225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 9972225a122SSuresh Siddha break; 9982225a122SSuresh Siddha } 9992225a122SSuresh Siddha #endif 1000e16b2781SRoland McGrath 1001032d82d9SRoland McGrath default: 1002032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1003032d82d9SRoland McGrath } 1004032d82d9SRoland McGrath 1005032d82d9SRoland McGrath return ret; 1006032d82d9SRoland McGrath } 1007c269f196SRoland McGrath 1008c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1009c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1010c269f196SRoland McGrath { 1011c269f196SRoland McGrath struct task_struct *child; 1012c269f196SRoland McGrath long ret; 1013c269f196SRoland McGrath 1014c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1015c269f196SRoland McGrath ret = ptrace_traceme(); 1016c269f196SRoland McGrath goto out; 1017c269f196SRoland McGrath } 1018c269f196SRoland McGrath 1019c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1020c269f196SRoland McGrath if (IS_ERR(child)) { 1021c269f196SRoland McGrath ret = PTR_ERR(child); 1022c269f196SRoland McGrath goto out; 1023c269f196SRoland McGrath } 1024c269f196SRoland McGrath 10253544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 10263544d72aSTejun Heo ret = ptrace_attach(child, request, data); 1027c269f196SRoland McGrath /* 1028c269f196SRoland McGrath * Some architectures need to do book-keeping after 1029c269f196SRoland McGrath * a ptrace attach. 1030c269f196SRoland McGrath */ 1031c269f196SRoland McGrath if (!ret) 1032c269f196SRoland McGrath arch_ptrace_attach(child); 1033c269f196SRoland McGrath goto out_put_task_struct; 1034c269f196SRoland McGrath } 1035c269f196SRoland McGrath 1036fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1037fca26f26STejun Heo request == PTRACE_INTERRUPT); 1038c269f196SRoland McGrath if (!ret) 1039c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1040c269f196SRoland McGrath 1041c269f196SRoland McGrath out_put_task_struct: 1042c269f196SRoland McGrath put_task_struct(child); 1043c269f196SRoland McGrath out: 1044c269f196SRoland McGrath return ret; 1045c269f196SRoland McGrath } 104696b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1047bf26c018SFrederic Weisbecker 1048bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1049bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1050bf26c018SFrederic Weisbecker { 1051bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1052bf26c018SFrederic Weisbecker return 0; 1053bf26c018SFrederic Weisbecker 1054bf26c018SFrederic Weisbecker return -1; 1055bf26c018SFrederic Weisbecker } 1056bf26c018SFrederic Weisbecker 1057bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1058bf26c018SFrederic Weisbecker { 1059bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1060bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1061bf26c018SFrederic Weisbecker } 1062bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1063